Isaac Lidsky was a teenager when he began to lose his eyesight. His pending blindness, though, actually drove him to graduate early from Harvard, clerk for a Supreme Court justice and build a family. He joins us this hour to talk about staying positive when life throws us a curve, which he writes about in “Eyes Wide Open: Overcoming Obstacles and Recognizing Opportunities in a World that Can’t See Clearly” (Tarcher Perigee).